Submergible pumping systems are widely used in the pumping of fluids, such as petroleum, from production wells. The typical submergible pumping system includes a variety of components assembled in a string for insertion into a wellbore, and ultimately into the fluid to be pumped to the earth's surface.
Numerous submergible components can be used in the submergible pumping system, but each system typically includes at least a submergible pump, a submergible motor to drive the pump, and a motor protector disposed somewhere between the submergible motor and the submergible pump. The string of components is deployed in a wellbore by, for instance, tubing, cable or coiled tubing. The production fluid, e.g., petroleum, is pumped to the surface of the earth either through tubing or through the annulus formed between the deployment system and an outer wellbore casing of the wellbore.
Regardless of the particular submergible pumping system used in a given application, it often becomes necessary to measure various parameters of the system. The measurements are particularly helpful if they can be performed during use of the submergible pumping system in the downhole environment of the wellbore. For example, it may be advantageous to measure parameters such as pump flow rate, pump speed, fluid temperature, fluid density, intake pressure as well as the oil dielectric in the motor protector. Present systems for measuring downhole parameters utilize separate units to measure, for instance, flow rate of the submergible pump. These separate units are typically expensive, add-on, stand-alone units that require special adaptation to the submergible pumping system for downhole operation. Often, such systems require extensive cable or valve arrangements to operate correctly.
It would be advantageous to have a simple sensor system that could be integrated into the string of submergible components for measuring submergible pump flow rates, and potentially other parameters of the submergible pumping system.